JL has a daily NRT-CAN flight
So the return from YYZ could be say ...YYZ-ORD-xNRT-oCAN-xNRT-oDEL-HKG
and presumably your friend can make his own way from CAN to HKG easily enough?
(I am assuming here that HKG and China are regarded as separate countries for the purpose of the "one departure from, one arrival to country of origin" rule)